4 Independence of the common mode coupling from the horizontal trace routing

It has previously been mentioned that only the vertical current segments of the trace couple to the cavity. Therefore, the trace introduction method only considers these vertical source and load currents in (5.6). Transfer impedance comparisons as described before are carried out for the two trace routings in Figure 5.7, to validate the independence of the coupling from the horizontal trace segments. The trace length in both models is l=110mm, the trace width $w_{t}$ =2mm, the trace hight above the ground plane is d=0.65mm, and the enclosure dimensions are (L=134mm, W=104mm, h=7mm). The comparison of the transfer functions to the meas port at (x=67mm, y=104mm) for the models in Figure 5.7(a) and in Figure 5.7(b) are depicted in Figure 5.8 and Figure 5.9 respectively. Comparison results of the transfer impedance to the other two measurement ports are presented in Appendix A.2

Magnitude and phase comparisons show a very good agreement of both models in Figure 5.7(a) and in Figure 5.7(b) to the results obtained with (5.6), (5.9) and the impedance matrix (4.17) from the model in Figure 5.7(c). That confirms the independence of the common mode coupling from the horizontal trace routing and validates the trace introduction method.

$\includegraphics[height=3.5 cm,viewport=75 470 520 705 ,clip]{pics/Encl_bend1.eps}$ $\includegraphics[height=3.5 cm,viewport=75 470 520 705 ,clip]{pics/Encl_bend2.eps}$

(a) Model a with trace.

(b) Model with a different trace routing.

$\includegraphics[height=3.6 cm,viewport=75 500 520 720 ,clip]{pics/Encl_bendP.eps}$

Figure 5.7: HFSS^® models with a different trace routing between identical source and load positions.

$\includegraphics[height=6.5 cm,viewport=180 285 420 500,clip]{pics/cZ/M1_b1_1.eps}$ $\includegraphics[height=6.5 cm,viewport=180 285 415 500,clip]{pics/cZ/A1_b1_1.eps}$

Load: 0 Ohm, magnitude.

Load: 0 Ohm, phase angle.

$\includegraphics[height=6.5 cm,viewport=180 285 420 500,clip]{pics/cZ/M1_b1_2.eps}$ $\includegraphics[height=6.5 cm,viewport=180 285 420 500,clip]{pics/cZ/A1_b1_2.eps}$

Load: 1e9 Ohm, magnitude.

Load: 1e9 Ohm, phase angle.

$\includegraphics[height=6.5 cm,viewport=180 285 420 500,clip]{pics/cZ/M1_b1_3.eps}$ $\includegraphics[height=6.5 cm,viewport=180 285 420 500,clip]{pics/cZ/A1_b1_3.eps}$

Load: 50 Ohm, magnitude.

Load: 50 Ohm, phase angle.

Figure 5.8: Transfer impedance from the trace source current to the slot measurement port at (67mm,104mm). Comparison of HFSS results from a model with a trace (Figure 5.7(a)) to the results obtained with (5.6), (5.9) and a HFSS model with ports.

$\includegraphics[height=6.5 cm,viewport=180 285 420 500,clip]{pics/cZ/M1_b2_1.eps}$ $\includegraphics[height=6.5 cm,viewport=180 285 415 500,clip]{pics/cZ/A1_b2_1.eps}$

Load: 0 Ohm, magnitude.

Load: 0 Ohm, phase angle.

$\includegraphics[height=6.5 cm,viewport=180 285 420 500,clip]{pics/cZ/M1_b2_2.eps}$ $\includegraphics[height=6.5 cm,viewport=180 285 420 500,clip]{pics/cZ/A1_b2_2.eps}$

Load: 1e9 Ohm, magnitude.

Load: 1e9 Ohm, phase angle.

$\includegraphics[height=6.5 cm,viewport=180 285 420 500,clip]{pics/cZ/M1_b2_3.eps}$ $\includegraphics[height=6.5 cm,viewport=180 285 420 500,clip]{pics/cZ/A1_b2_3.eps}$

Load: 50 Ohm, magnitude.

Load: 50 Ohm, phase angle.

Figure 5.9: Transfer impedance from the trace source current to the slot measurement port at (67mm,104mm). Comparison of HFSS results from a model with a trace (Figure 5.7(b)) to the results obtained with (5.6), (5.9) and a HFSS model with ports.

			Dissertation Christian Poschalko
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5.4 Independence of the common mode coupling from the horizontal trace routing